Infestation and Damage Caused to Vitellaria paradoxa Gaertn, F. (Sapotaceae) by Cirina forda Westwood [Lepidoptera: Saturniidae J in Benue State, Nigeria.

Abstract

The infestation of sheabutter tree, Vitellaria paradoxa Gartner. F., by the pallid emperor moth, Cirinaforda Westwood, was studied from 2004-2006 in Aye Gber and Akaa Pila in Benue State, Nigeria. Observations were made on adult emergence from soil, copulation behaviour, oviposition, incubation period, larval density, feeding within tree canopy, damage, and natural enemies. Ten leaves were randomly selected from the lower, middle, and upper strata of the crown and the numbers of larvae on them were counted and transformed to (x + 0.5)1/2 for analysis. Defoliation was rated on a scale from 0-2 and transformed to Log 10 before analysis. Moths of C. forda emerged from the soil around the base of V. paradoxa from the last week of May in each year. Larval densities were high in the first two weeks of sampling, declining significantly thereafter. Larval density was significantly higher (P<0.05) in the lower stratum of the crown compared to the middle or upper stratum. Locational differences in larval density were not significant (tu>0.05) although numerically higher density was observed at Aye Gber than at Akaa Pila in 2004 -2006. The trees were partially defoliated in 2004 and 2005 but were completely defoliated in 2006 at both locations. Three insect predators: Crematogaster sp. nr perrisi, Camponotus sp. and Oecophylla longinoda (tailor ant) were noticed preying on C. forda eggs and larvae.